Sound recording device



'April 26, 1932. P. A. ROBBINS I SOUND RECORDING DEVICE Filed se t'. 19, 19:0 2 Sheets-Sheet 1 April 26, 1932. P. A. ROBBINS SOUND RECORDING DEVICE v Filed Sept. 19, 1930 2 Sheets-Sheet 2 i Patented Apr. 26, 1932.

, UNITED STATES PATENT. OFFICE PERCY A. ROBBINS, F HIGHLAND PARK, ILLINOIS sounn Brooms-me nnvrcn Application filed September 19, 1930. Serial No. 482,994.

" for use as a substitute forthe delicate wax cylinders commonly employed as dictograph' records. Records of this type are shown and described in my co-pending applications Nos. 445,781 and 445,782, dated April 19th, 1930, and the object of the present invention is to provide simple and eflicient apparatus for mechanically producing such records.

I attain my object by utilizing a travelling flexible ribbon as a diaphragm adapted to be vibrated, by sound waves concentrated thereon by means of a suitable horn, against a cutting tool adapted to engrave the surface of the travelling ribbon in accordance with the frequencies of the sound waves impinging thereon. A record so produced will have the 7 required characteristics and, according to the nature of its material may be used to reproduce the recorded sound in known ways. j A typical form of my invention is illustrated in the accompanying drawings in which j Fig. 1 is a front elevation partly in section, the driving means being omitted;

lig. 2 a perspective view of a modification; an

Fig. 3 a vertical section through the throat of the horn looking towards the travelling ribbon.

In the drawings like numerals of reference indicate corresponding parts in the different figures.

Referring. to Fi a frame suitably s 'aped to support the different parts. On this frame is pivotally supported, preferably removably, the storage reel 2-carry1ng'a roll offlexible record ribbon 3. This record ribbon may be such a ribbon as is shown and described in my copending application No. 445,782; that is, a flexible film which will pass light rays in proportion to' the extent to which its surface is engraved by-a cutting 'tool and which may be either a thinning of the material, the production of engraved areas of varying extent, or-

both. If, however, the-record is be re- 1 of the drawings, 1 isproduced by the mechanical operation of a stylus, the quality of translucency is not required. In any case, however, the ribbon -must possess the qualit of vibratibility be driven in any suitable manner. An adjustable friction brake 11 ofknown type is providedv whereby the ribbon may be tensioned to any extent necessary.

Behind the ribbon is located a rotary cutter 12, which may be a fine toothed milling cutter. This cutter is secured to a shaft 13 j ournalled in the frame 1 and provided with the pulley 14 by means of which the cutter may be driven at any desired speed by any suitable motor.

15 is a horn which may be of any suitable type adapted to collect atmospheric sound waves and to cause them to impinge on the travelling ribbon 3. To designa suitable shape of horn for this purpose and to properly'load the ribbon diaphragm is within the scope of anyone skilled 1n the art. When the cutter and ribbon are in mottion, as hereinbefore described, and sound waves are collected by the horn, the ribbon 3 being under tension vibrates as a diaphragm and engagesthe revolving cutter 12. A sound trace is thus engraved on the ribbon surface, as in the copending application hereinbefore referred to, and the engraved record thus obtained may be used to reproduce sound as referred to in the preamble to the specification.

In Fig. 2 of the drawings a slight modification is shown. A'pair of rollers 5 replaces the roller 5'and apair of guide rollers 16 is added adjacent the born 15. The rollers T5 and l6'may be positioned to limit the length of the ribbon vibrating as a diaphragm as may be found desirable.

The shaft 13 of the rotary cutter 12 is positioned horizontally and the guide rollers 5 and 16 are positioned to guide the ribbon diathus adapted to engrave the ribbon as the latter is moved past it.

The cutter shaft is j ournalled on a slide 17 movable on the guides 18 to-and-from the ribbon and an adjusting screw 20 is provided whereby the slide may be adjusted to bring the cutter and ribboninto the proper position for co-operation. The rollers 6 and 7 are shown as driven by worm gearing 19.

What I claim as my invention is:

1. Apparatus for making sound traces on sound records comprising a continuouslymoving driven cutting element; means for moving a flexible vibratible record ribbon past the cutting element with one of its flat surfaces presented to the cutting element within the limits of vibration of the ribbon;

and means for directing atmospheric sound and ahorn having its throat positioned in proximity to the record ribbon whereby the latter forms a diaphragm for the horn and is 7 ca used toefiect a cutting engagement between itself and the cutting element to produce a sound trace corresponding to sound waves received by the horn.

' 3: Apparatus for making sound, traces on sound records comprising a continuouslymovingdriven cutting element; meansffor moving a fiexible vibratible recordribbon. past-the cutting element with one of its flat surfaces presented to the cutting element within the limits of vibration of the ribbon; adjustable means for tensioning the record ribbon; and means for directing atmospheric sound waves against the record ribbon to cause a cutting engagement between the record ribbon and the cutter to produce a sound trace corresponding to the sound waves.

4. Apparatus for making sound traces on sound records comprising a continuouslysound records comprising a continuouslymoving driven cutting element; a flexible vibratile record ribbon mounted to travel past the cutting element with one of its flat surfaces presented to the cutting element within the limits ofvibration of the ribbon; and means for vibrating the ribbon in a direction normal to the said flat surface in correspondence with sound waves.

Signed at Highland Park, 111., this 28th day of August, 1930.

PERCY A. ROBBINS.

moving driven cutting element; means for moving a flexible vibratible record ribbon past the cutting element with one of its flat surfaces presented to the cutting element within the limits of vibration of the ribbon;

adjustable means for tensioning therecord ribbon; means. for directing atmospheric sound waves against the record ribbon to cause a cutting engagement between the rec- 0rd ribbon and the cutter to produce a sound trace corresponding to the sound'waves {and means for "adjusting the cutter toand-from 5 5. Apparatus for making sound the surface of the ribbon.., v

traces on 

